Vacuum cooker



April 24,1945. R; KROUT v 2,374,216

VACUUM-COOKER v Filed Nov. 29, 1938 2 Sheets-Sheet} INVENTOR BY FAY W hkouf I WMf/MM ATT ORNEY April 24, 1945. w KRQUT VACUUM 000m;

Filed NOV. 29, 1938 2 Sheets-Sheet 2 BYPAQNVV711EZUT 7M4 ATTORNEY Patented Apr. 24, 1945 VACUUM COOKER Ray W. Krout, Paterson, N. J assignor to Charms Company, Bloomfield, N. J.,

Delaware a corporation of Application November 29, 1938, Serial No. 242,991

Claims.

The invention relates to improvements in cookers, evaporators and the like, for the treatment of various substances by heat and distillation or dehydration; or heat alone if no further step is required.

In the manufacture of candy, sugar is reduced to syrup of various densities, preferably by means of water and heat, with or without other ingredients, the most common of which is corn syrup. The crystal form of the sugar vanishes in this change. The effect of heat on any mass will vary with the ingredients thereof, the temperatures and the length of time the mass is subjected thereto. When invert sugar is generated in the syrup, heat will cause the breakdown of the less stable substances, resulting in caramelization and formation of different products, and discoloration of the mass. Individually, these products may or may not he wanted. As a rule, the higher the temperature to which the mass is subjected, the more undesirable are the results; and, of course, the best practice is to accomplish the desired treatment with a minimum expenditure of heat and time.

The ingredients of the syrup must be thoroughly intermingled and heated in a suitable vessel, and the sugar is thus converted from crystalline into amorphous form. During the heating the moisture can be expelled wholly or in part, or not at all, according to the kind of candy desired. The mass so obtained, which is fluid and very viscous, is cooled and flavored in preparation for the next stage; or the flavoring may be done while the heating is in progress.

The vaporization and removal of moisture from the syrup can be facilitated by creating a partial vacuum above the syrup. However, in the process of vaporizing water from a mass of syrup in a partial vacuum, the force of the escaping vapors agitates the syrup and lifts its level; so that if not prevented some of the syrup will be carried off with the vapor and lost. I have therefore developed .a container of such character that a relatively great quantity of syrup therein can be spread out in a comparatively shallow pool or layer with an extended liberating surface on top, which necessitates a relatively small surge distance. This container also encloses sumcient space above said surface to receive released vapor, with an outlet flue of some length rising vertically from the top; and said container further has a heating jacket so disposed as to give a rapid heating effect. By means of a vacuum in such an apparatus to expedite vaporization when necessary, the extraction of moisture can then be accomplished in a very satisfactory and inexpensive manner. f Conveniently, the heat-carrying medium is steam, and, as above stated, the mass is also put under a vacuum, when necessary, for dehydration and cooling of the mass of syrup. To realize these ends I find that a suitable apparatus should have the following characteristics: maximum practical heating surface in proportion to the mass to be heated; maximum practical liberating surface in proportion to the mass to be heated and subjected to vacuum; capacity to hold a mass or batch in such a way that there will be a maximum and fairly uniform head through which the moisture in the mass, which has been converted into steaim, will pass on its way to the liberating surface where it is extracted from the mass; a heating surface giving free and easy circulation of all steam, vapors and gases passing from the heating surface to the liberating surface, permitting no obstruction through the mass; and ample space above the liberating surface to accommodate a maximum surge or elevationof the mass while under vacuum. I

Such apparatus in operative form will afford the following advantages: easy charging of the mass; easy discharging of the finished batch, requiring only a minimum carry-over of the completed batch to the succeeding batch; capacity to process a comparatively large mass and automatically divide same into two workable-size batches when discharging, or discharge entire batch from either end; treatment of each batch as a unit, leaving virtually no material partially processed after the shutting down of the unit; also making possible the variation of the composition, if desired, of every succeeding batch; elimination of the necessity of any mechanical agitation of the mass while being processed, if not-desired; the discharging'of the batch directly on a cooling or conditioning table for further treatment at a uniform temperature and predetermined rate of flow, without risk of one batch contaminating a previous or a succeeding batch; observation of the mass during the entire operation; indications by instruments so arranged in the mass as to reveal what is occurring in the process; and sampling-through ports so that a specimen of the mass can be extracted any moment without interfering with or retarding the process.

, In general, it is the object of my invention to provide an improved type of cooker or evaporator These and other objects will be clear to oneskilled in this art, after a reading of the specification taken in connection with the annexed drawings, wherein: i t

On said drawings: Figure 1 is a side view of an improved cooker for hard sugar candy, and its connections;

Figure 2 is a front view thereof;

Figure 3 is a top view thereof in part; showing chiefly the connections;

Figure. 4 is a vertical. section (enlarged) taken longitudinally through one end of the casing, of the cooker, with the gate therefor closed;

I Figure 5 shows on an enlarged scale the configuration of. the inside of an end ring for, the shell or body of the cooker; U

Figure 6 is an'enlarged end elevation of. said. casing, showing the shape of theinterior;

Figure 6a shows an accessory for the cooker..

In. the drawings the 'same numerals identify the same parts throughout.

As shown in thesefigures, the cooker is made to comprise a horizontal casing, I elongated in form, supported onposts or stanchions 2. At the top of the casing is an inlet pipe 3 toadmit the charge of syrup; the casing. has also. a vertical stack or. flue 4 to carry away gases and/or vapors that must be expelled from the charge. On the bottom of the casing. I is an outside jacket enclosing achamber, 5 to receive a heating medium such as steam. Swinging gates 6 are mounted at the ends of the casing andwhenever the "processing of a batch of syrup is finished,

one or both of these gates are opened so that the syrup can be extracted. The exterior of the casing I. andof the steamja'cket 5'.can be covered withheat-insulating material 'I, Fig 4,, over which an envelope of thin sheet steel may be laid, if desired: At 5' is a. drain for water of condensation in the jacket '5'.

To the inlet pipe 3 is connectedv a T'-coupling. 8, a syrup line 9 and 'a water supply pipe [0. Each pipe 9 and ID has a valve If so. that'onev can be. cut off when the .other is needed. 'The supply pipe 9 runs to a pre-melting kettle or vat wherein the sugar and water or other mixture is heated andmixed to make syrup of the quality desired. After the melting and mixing the syrup' is passed in through the pipe 9. into the casing I. When thecasing is not in operation it can bewashed out with water delivered. through the water pipe I. The charge'is run. into; the

cooker through the conduit 9 by gravity when the pre-cooker isv higher than the casingv l; or by. forcing it by creating a vacuum in the cas ing when-the pre-cooker isat a. lower level;

Steam flows. into-the jacket through pipe t2. connected by branches toboth: ends of the casing.- In this pipe is a valve l3 to enable the operator to turn the steam on or off at will. Above this valve, a branch pipe l-4- leads; from the steam pipe l2 to a steam ejector [-5, which discharges through an exhaust pipe-116;. The upper portion of. the outlet-stack 4 .is united by a conduit I! to a condenser l8, placed below the casing. A vacuum of the required degree is created in this condenser by the steam ejector [5, which is put into or out of operation by a separate valve 13 in the steam pipe l4. Being in communication with the condenser through the flue 4 and conduit I1, the casing I has the same pressure below atmosphere in it as the condenser I8. The conduit I11: is open and closed by a valve I'9 therein nearthe upper end of the flue 4. The amount of moisture to be extracted from the syrup is regulated by the action of. the' ejector I5 which fixes the degree of the vacuum in the casing I.

To theheating. jacket a steam return line 20' is joined;,.ancl.this line has a valve 2i therein,

26. To actuate the valve 26; agear 21 is.- fixed on. the outer end of its stem, to mesh with a gear 28 on a rod 29; This rod extends down to the top of the casing and has its: lower portion engaged by a bearing. in abracket 30 on the flue 4. At itsupper end it is-received in a bear.- ing 3t, fixed to the flue 41. Another rod' 32: is connected to the valve. Hi to open and close' this valve and-,this rod is: also engaged inabracket 30 on the flue 4'nearitslower end. The attendant can rotate these rods by grasping the knobs 35- at their lower extremities. Mounted. on. the 11:64.18 a vacuum gauge 33: and a safety valve 3 To the extremities ot the tubular casing and jacket are secured end rings 36. To these end rings are affixed the. gate rings 31. The'ring 31- abut the extremities of the casing I and have-inside conicalsurfaces38. In'cross section the'casing l., madeof metal. plate, is not circular-inside but preferably dome shaped with an, arc. 39 at.

the top. of relatively small width and radius from which thesides, diverge tolthe bottom:40, whioh is flat or concave butof relatively great. widthand radius. The inside otthe casing between. the top and bottom isal'so concave to make it better able to resist outside pressure when a vacuum isomeated' in said casing. Theconical': surface.- 38 of each gate ring 31 is cut atthe double-curved line 41 to suit, and continue into the ringstflthe in.- side circumferential curvature. of the tubular casing I;v the part 38. of the. inside surface ot the rings 31 thu blendingv with theinside. of the casing; the inside surface 38. of the. rings 31. remaining' conical. outward, of this line. 4 l' of, intersection with the inner curvature of. the, casing. Withthis construction a large quantity of' syrup can be treated in the casing I? without. filling the latter to very great depth because of. the. large area of the bottom; and: the top offthesurface of each batch will be quite extensive,facilitating, the liberation ofmoisture from. the massinto the. space aboveit. This space is big enough to accommodate the up-surge of the'mass'whil'e under vacuum.

Eachgate ring 31 has two aligned: horizontal bearingst'l. at the top, one on each-side to receivethe ends-eta fulcrum shaft 43. Ea'chiswingingr gate: 6-has a pair of lugs or bearings 44 to receive the ends of a shaft 45 the extremities of which are connected to the outer ends of the shaft 43 by link 46. These gates are ofcourse conical to fit the gate rings 31 and make a tight joint. Each of the gate rings 31 also has studs 41 at opposite sides. On the ends of the shaft 45 beyond the links are hooks 48, each having a handle 49, so that the hooks can be turned to move them and make them engage the studs 41 and hold the gates shut tightly when the syrup is undergoing treatment, or swung to release the gates to enable them to be opened. The gates may be rigid on the shafts 45 and the links 46 may also engage these shafts 45 rigidly, and rigid with the links and extending upward along same to a point above the cooker are arms 50 bearing counterweights in such position as to make opening the gates easy; For convenience; only one hook 48 is shown in Figure 2.

The ends gates 6, rings 31, links 46, hooks 48, and some other details are omitted from Figure 3, as this view is intended to show only the general positions of the casing I, table 52, and various pipe connections, all of which will be the same at both ends of the cooker. In this figure, one end is not presented; but is of course a duplicate of that actually illustrated.

In operation the vacuum in the condenser I8 and casing I causes vaporization and release of moisture from the syrup in the casing, and the heating eifect is concentrated by the steam jacket as needed. This moisture is withdrawn through the pipe 4 into the condenser "I8 where it is condensed by the operation of the cooling water, and thus liquified again. When no moisture is to be extracted, as in making some kinds of candy, the ejector I5 is not used and no vacuum in the easing is created; and the casing is heated only.

The use of a condenser is not essential in all cases and may then be dispensed with.

With this apparatus, because of the vacuum, moisture in the syrup can easily be removed. The control of the heat prevents scorching and discoloration or disintegration of the syrup. Therefore the syrup, when it is withdrawn still warm from the casing, will .be clear and transparent; and the flavoring substance can then be added and well mixed into it. Being clear, the syrup will not only have the appropriate taste after the flavoring compound is introduced, but also it will assume an attractive and appetizing appearance; and when colored present a true shade such as red for cherry, green for lime, etc.; and a most dainty material for confectionery is thus obtained.

At each end of the casing I is a cooling table or tray 52 with low sides, mounted on legs 53, connected by cross braces 54. The bottom of these tables are hollow, and are connected to cold water pipes 55 and 56, one for each half of the tables. At one corner of each table the side has an opening connected to a drain pipe 51 for wash Water. These tables receive the charge after treatment.

The condenser I8 has inlet 58 for cooling water and an outlet 59 through which the cooling water is discharged. Below the condenser is a horizontal receiver 60, connected to the condenser by a line 6 I, having a shut off valve 62. Vapors from the casing I liquified in the condenser, thus pass to the receiver. At 63 is shown a vent line, with a similar shut-ofi valve 62, between condenser and receiver; which also has a valved draw-01f pipe 64, in one end at a suitable height, and a sight glass 65. Any oils, recovery of which is desired, float on top of the liquid deposited in the receiver, and can be extracted by way of pipe 64. At 65 the receiver has a valved drain pipe to empty it. Pipes for admitting and carrying off water are of course coupled to ports 58 and 59.

To facilitate washing out the cooker there is a, pan 61 below each end. Afi'ixed to the bottom of each pan is a pair of rods 68, secured by lugs 69. These rods slide in tubular guides 10 which extend horizontally below each side of the cooker, being mounted on arms 1| inside the stanchions 2 and secured thereon. The pans have outlets to. which are attached drain pipes 12, having swivelled sections 12' to enable the pans to be moved without displacing the pipes 12.

When the cooker is cleaned the pans are pulled out to be beneath the ends of the casing to catch water discharged by it. The water runs through pipes 12 to the sewer. When the cooker has been cleaned the pans 61 are pushed, forcing the rods 10 into the guides 1|, back under, the casing I.

Though provided for each pan 61, only one swiv-' elled pipe 12 is shown in Figure l, the pipe for the other part being identical. The tables 52 and pans 61 are omitted in Figure 2, for the sake of clearness.

The casing projects at its ends beyond the condenser and receiver for better advantage in discharging and washing.

The casing I may have a connection 13 at the top to be plugged until needed, for an auxiliary chamber, so that invert sugar or any other substance can be run into the batch when treated. In either gate is a temperature gauge 14. The gates also have sight glasses 15 held in place by flanged rings 16 over openings 11, and a reflector 18 containing an electric light '19 is attached to the ring 16 of one gate so as to reflect the light into the interior of the cooking chamber and so enable the attendant to watch the operation through a sight glass in the opposite gate. See Figure 4. Current for the light is supplied by conductors 80. A handle BI on each gate enables the operator to grasp the gate and swing it up to open the cooker.

The stanchions 2 are braced by cross bars 82, and the receiver is supported on feet 83. On plates 84 carried by the receiver rests "the condenser I3. On top of the casing are lifting lugs 85.

If it is desired to mix the flavors with the batch during the process or at the end, before the contents of the cooker are discharged on the end tables 52, several vessels, two of which are shown at 13a and 13bin Figure 6a, may be connected to a pipe 4a coupled to the outlet flue 4. These vessels will each be joined to the conduit 4a. by pipes at the bottom having therein valves 130. When these vessels are filled, each with a different flavoring material, the contents of any one of them can be run into the casing I by opening the valve 13c beneath same. These vessels can be supported as required, and they may of course be united to a connection like that at 13, as well as to the flue 4.

As an example of the operation for the manu iacture of hard candy, 300 pounds of refined sugar is melted down with poundsof water and brought to a boil in a vessel connected to line 9.

Any inverting agent may be used, the quantitybeing varied in accordance with the percentage of invert sugar wanted in the finished product. This inverting agent can be added just before the melted syrup is drawn in to the cooker or at any time during the melting process or it can be added in the cooker before the melted syrup is Partly processed. As the generation of invert sugar is dependent upon the amount of inverting agent, the. ternperature to which this mass is subjected and the length of time to which itis subjected to temperature, it is necessary to workout a proper balance of these three variables to get consistent results, keeping in mind the fact that invert sugar is a very unstable product and breaks down very quickly under heat; hence it is desirable to subject the invert sugar generated to as little high temperatureas possible. It is also possible to get the required amount of invert sugar into the finished product by not generating it during the process with an inverting agent as has just been described, but by introducing into the batch the correct percentage of invert sugar. It is also desirable to introduce the invert sugar into the mass as late as possible in the heating process, so as to subject it to the minimum amount of heat.

If the premelted sugar is to be run into the cooking chamber by gravity, it will be necessary to have valve 1 I open in the syrup line 9, also to open valve 26 to atmosphere.

If the premelted batch is drawn into the easing I byvacuum, the attendant must open valve II in the syrup line, close valve 26 to atmosphere, open valve l9 in xvacuum line Hand give the steam ejector control valve 13 about one turn, so that about five or six inches of vacuum is obtained in the cooker to pull the batch in.

After the entire batch has been drawn into the cooking chamber, the valve I3 in line H is opened to allow high pressure steam to flow into the steam-jacket of the cooker, and the valve 26 is opened so that the steam vapors from the cooking chamber can find their way through the outlet 25 to atmosphere. It is advisable to close valve IS.

The cooking from this point up to the desired temperature is done under atmospheric pressure. When gauge 24 registers the predetermined temperature, the steam supply is shut off by closing the valve l3, the valve 26 is closed to atmosphere, and the valve I9 is opened in the vacuum line Ii. Also the valve I3 is opened, supplying steam to the ejector 45. The vacuum gauge 33 should respond immediately and show approximately 24 inches with 20 or 30 seconds-and continue on to 27 or 28 inches in an additional 30 seconds. Higher Vacuum may be attained by using multistage ejectors.

The temperature gauge 24 will now show a rapid drop when .the vacuum is created, but when all moisture is out of the batch, the temperature will practically stop falling. At this stage the batch has had vacuum enough, valve I3 is then closed, so as to shut off the steam ejector I5, and the valve 26 is opened so as to break the vacuum and open the cooking chamber to atmosphere. The end gates 6 are opened simultaneously and a portion of the batch will flow at once out of the cooking chamber on each cooling table. While this is discharging the attendant at each end scrapes ofi whatever candy adheres to the gates, and then with an extracting hoe, reaches into the center of the cooker and pulls out the balance, giving 150 pounds on each cooling table 52. The attendants then remove whatever part of the patch adheres to the lower portion of the ground seats for the gates. They; then pull out pans 61 over the batch on the' cooling table and under the gates and complete the cleaning of the ground surfaces with wet cloths or wet scrubbing brushes. The gates G are then closedand locked and the'cycle repeated by drawing in another premelted batch, The pans, 61, should always be pulled outslightly, in case there is any slight leakage of syrup from the gates due to the surfaces not being thoroughly cleaned.

. After the batch has been'brought up to predetermined temperature, the vacuum should be quickly applied and the charge removed from the cooker. to the cooling tables 52 as rapidly as possible. 'The less time the sugar is subjected to high heat, the less carmelization will occur, and a better color result. As the cooker has a large heating surface which retains its heat after the steam supply has been shut off by closing valve l3, the batch will discolor unless the cooker is discharged promptly, The valve [3 must always functiodproperly, and not allow any steam to seep into the jacket when it is closed.

To obtain exceptionally clear product, the heating jacket can be converted into a cooling jacket as soon as the vacuum is started. This can be done by joining a water pipe to the steam supply line at the T under valve I3. Then the batch iscooled with the vacuum from above and cold water below. If one operates the cooker in this manner, care should be taken so as not to develop water hammer. The cooker is built with a high factor 'ofsafety as to withstand such severe conditions.

As another example of the operation, in the manufacture of grained mints, generally known as after dinner mints, the operation is similar to the manufacture of hard candy except that the temperature to which the mass is brought is not ashigh and the vacuum is held longer so as to arrive at'the desired percentage of moisture in the finished product.

In the operation of manufacturing syrup for cream fondant, the cooker does not raise the temperature of the mass, but is used entirely as cooler. The combination of sugar and water is brought up to the desired temperature in a precooking kettle, drawn into the cooker by vacuum and high vacuum is then applied for the purpose of withdrawing surplus moisture and cooling the mass, In this process, the steam jacket maybe used as a water jacket by running cold water into it instead of steam, and so facilitate the cooling, accomplishing the cooling both by vacuum and by surface cooling against the cold bottom of the casing chilled by the circulating water through the steam jacket. The required percentage of moisture in the finished product can be obtained by. varying the temperature to which the syrup iscooked and the length of time under which vacuum is applied. If desirable, the bringing of the mass up to the required temperature can be done in the cooker, thus eliminating the pro-cooking kettle. However, the mass can be cooled to a lower temperature when the cooker is used only as a cooling chamber, and the necessary cooking done in another container. In this operation, the vacuum is the principal cooling agent; and because of the shape of the chamber containing the mass, it can be spread over a big area with a large liberating surface and comparatively smallhead, so that the mass is in the most desirable form on which the vacuum can operate.v

Obviously, with this form of my invention the casing can be built with only one gate and the other end permanently closed if desired, or it may beworkedby'using only one of the gates to discharge through one of the ends.

It will be noted that the jacket is placed at the bottom of the casing adjacent the parton which the charge of syrup rests, and is substantially vco-extensive with the bottom and the lower part of the sides of the' casing. The heatingmedium thus comes into contact directly with only the part of the casing carrying the charge; this arrangement applies the heat most advantageously.

A great advantage which this invention thus far described affords is the spreading out of the mass of syrup in the casing to a smalldepth over a large heating area; see particularly in Figure 6, where the syrup is indicated by the dashed line upon the wide bottom 40. The spreading out of the syrup in this way enables it to be heated quickly and effectively, because the heating jacket 5 lies under the bottom of the casing on which the syrup rests, and overlaps the adjacent lower portions of the sides. The syrup thus presents a large surface at the top through which the vaporized moisture can pass and be liberated; being drawn out through the exhaust pipe 4. Because of the shallowness of the syrup the particles of moisture, as they are volatilized and extracted, have only a short mean or average distance to travel before they pass through the top or liberating surface of the syrup, and are free. The casing forms a space of sufiicient volume above the syrup to contain all of the moisture liberated as it flows to the outlet flue 4,.while retaining the entire agitated mass of the syrup. Owing to the height of the space above the syrup and the length of the vertical flue 4 the risk of some of the syrup being carried out through the pipe 4 and lost, is obviated. By watching the operation through the glass 15, the operator can control the action of the ejector 15 or the like, so that none of the syrup is ever lost through'the outlet 4.

In other words, when moisture in the syrup is vaporized it is really converted into steam; and the force of the steam, as it rises from all points in the batch and escapes through the upper surface thereof, would, if the space above the syrup and the height of the flue 4 were not ample, carry the syrup up to the top of the casing and discharge some of it through the outlet 4.

By imparting to the casing the arched crosssectional shape shown in Figure 6, the inside of the casing is sufficiently bowed or concave at all points to resist atmospheric pressure when evacuated and steam pressure above the steam jacket. I have found that as the depth of the batch of syrup in the casing is increased, the height of the space which must be present above the surface increases out of direct prooprtion; and therefore, unless the apparatus is carefully designed, it would have to be much higher and a great deal more material used in constructing it. But with a casing having the dome-shape disclosed herein, with a wide slightly concave bottom of great length so that the syrup can be spread out shallow and present a large upper surface, and with the flue 4 high enough, the space required above the syrup is reduced to a minimum and the amount of material needed is also kept within proper limits.

The attachment for getting a sample from the batch can be mounted on either or both gates or at any other convenient point. It comprises a short pipe 81 (Figure 1) that communicates with the inside of the casing I, and on the outside this pipe has two hand valves 88 and 89. By

keeping valve 88 closed and opening the other for the sake of clearness.

valve, the pipe 81 will'fill with:enough ofthe syrup to enable a test to be made Thenthe valve 89 is closedand the valve 88 opened. This sample can be extracted without interfering with the vacuum in the casing I. The showing of this attachment is omitted from the other views The apparatus thus far set forth with its extended heating surface and. extended vapor liberating' surface, the method of charging, discharging and various mechanical details have given excellent results in the manufacture of hard candy, grained mints and the preparationof syrup for cream fondant and cake icing; The invention, however, is not limited; to thisfield but may be practiced for the distillation and/or de'- hydration of various materials; v 1' Thus the above constructions have all of the features of design to ensure the aims, purposes, and advantages of the invention. With the constructions presented a large batch can be treated in a few moments safely and thoroughly,

From what has been said, it will be understood thatvarious changes may be made in the details entering into the construction of the type of cooker disclosed herein. For example, by way of illustration but not of limitation, an evacuating pump may be employed, instead of the steam ejector described, but all such changes are believed to come within the spirit of my invention and the scope of the appended claims.

Having described my invention, what I believe to be new and desire to protect by Letters Patent is:

1. A cooker comprising a horizontal tubular casing having a closure gate at its end, a jacket enclosing a chamber at the lower part of the casing, a vertical outlet stack for the'casing, the stack having a valved outlet to the atmosphere, a condenser below the casing connected to the upper part of said stack, means for evacuting said condenser and casing, a receiver, below the casing condenser and connected to the condenser and having an outlet to deliver part of the con tents of the receiver, said end of the casing projecting beyond the condenser and receiver, a table beneath said gate to receive the contents of the casing, means for cooling the table, a pan adjacent the gate, rods aifixed to the pan, and guideways slidably receiving the rods between the casing and condenser, to enable the pan to be supported under the casing and drawn out under the gate when needed.

2. A cooker comprising a horizontal tubular casing having a charging inlet, means for heating and means for evacuating the casing, a gate at the end of the casing to enable the contents of the casing to be extracted, a table beneath said gate to receive the contents and spread the same thereon, means for cooling the table, and a pan slidably supported under the casing and above the evacuating means, to be drawn out into position under said gate when needed.

3. A cooker comprising a horizontal tubular casing having a conical closure gate at its end, the casing being dome-shaped in cross-section with a relatively wide bottom, and having a gate surface of the casing, said surfaces on the ring intersecting in a double-curved line.

4.,A cooker including an elongated, horizontally positioned tubular casing having a conical closure gate at one end, the casing being domeshaped in cross-section with a relatively wide bottom, and having a ring at said end for said gate, the ring having a conical inside surface, and another surface blending with the interior of the casing, said surfaces of the ring intersecting in a. double-curved line, a jacket enclosing a chamber at the lower part of the casing, a vertical outlet stack for the casing having valved connection with the atmosphere, a condenser under the casing and connected to said stack, said end of the casing projecting beyond the condenser, means for controlling the pressure in the con- 1 and condenser adjacent; said gate to be pulled out when needed.

5. A cooker comprising a horizontal tubular casing having a conical closure gate at its end, the casing being dome-shaped in cross-section with a relatively wide bottom, and having a gate ring secured at said end for said gate, the ring having a conical inside surface and another surface blending with the interior surface of the casing said surfaces on the ring intersecting in a double-curved line.

RAY W. KROUT. 

